The primary goal of this project is to detemine if the replication of various members of the human herpesviruses can be modified by modifying the pattern of host DNA synthesis in the infected cell. The replication of the human herpesvirus varicella-zoster (VZ) in human embryonic lung (HEL) cells serves as the model system. The first experiments have been performed to characterize the pattern of cell and viral DNA synthesis in the productive infection of HEL cells. A modification of the differential salt precipitation of Hirt technique (Rapp, et. al., Intervirology 8:272-280,1977) has been used to separate viral DNA cell DNA for quantitation of the rate of synthesis of each. Viral antigen expression will be followed by using immunofluorescent antibodies. Various procedures will then be used to modify the pattern of cell DNA synthesis and to follow the effect on VZ virus replication. The first technique used has been pretreatment of cells with the thymidine analog iododeoxyuridine (IdU) rpior to infection with VZ virus. Other techniques to be used include theuse of synchronized cells,nonconfluent monolayers, and serum starvation.